building web apps for everyone

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Building Web Apps for Everyone
Adam D. Scott


Building Web Apps for Everyone
by Adam D. Scott
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978-1-491-95552-9


[LSI]


Preface
As web developers, we are responsible for shaping the experiences of users’ online lives. By making
ethical, user-centered choices, we create a better Web for everyone. The Ethical Web Development
series aims to take a look at the ethical issues of web development.
With this in mind, I’ve attempted to divide the ethical issues of web development into four core
principles.
Web applications should work for everyone.
Web applications should work everywhere.
Web applications should respect a user’s privacy and security.
Web developers should be considerate of their peers.
The first three are all about making ethical decisions for the users of our sites and applications. When
we build web applications, we are making decisions for others, often unknowingly to those users.
The fourth principle concerns how we interact with others in our industry. Though the media often
presents the image of a lone hacker toiling away in a dim and dusty basement, the work we do is quite
social and relies on a vast web of connected dependencies on the work of others.
What Are Ethics?
If we’re going to discuss the ethics of web development, we first need to establish a common
understanding of how we apply the term ethics. The study of ethics falls into four categories:
Meta-ethics

An attempt to understand the underlying questions of ethics and morality
Descriptive ethics
The study and research of people’s beliefs
Normative ethics
The study of ethical action and creation of standards of right and wrong
Applied ethics
The analysis of ethical issues, such as business ethics, environmental ethics, and social morality
For our purposes, we will do our best to determine a normative set of ethical standards as applied to
web development, and then take an applied approach.
Within normative ethical theory, there is the idea of consequentialism, which argues that the ethical
value of an action is based on the result of the action. In short, the consequences of doing something


become the standard of right or wrong. One form of consequentialism, utilitarianism, states that an
action is right if it leads to the most happiness, or well-being, for the greatest number of people. This
utilitarian approach is the framework I’ve chosen to use as we explore the ethics of web
development.
Whew! We fell down a deep dark hole of philosophical terminology, but I think it all boils down to
this:
Make choices that have the most positive effect for the largest number of people.
Professional Ethics
Many professions have a standard expectation of behavior. These may be legally mandated or a
social norm, but often take the form of a code of ethics that details conventions, standards, and
expectations of those who practice the profession. The idea of a professional code of ethics can be
traced back to the Hippocratic Oath, an oath taken by medical professionals that was written during
the fifth century BC (see Figure P-1. Today, medical schools continue to administer the Hippocratic
or a similar professional oath.


Figure P-1. A fragment of the Hippocratic Oath from the third century (image courtesy of Wikimedia Commons)

In the book Thinking Like an Engineer, Michael Davis says a code of conduct for professionals:
prescribes how professionals are to pursue their common ideal so that each may do the best she
can at a minimal cost to herself and those she cares about… The code is to protect each
professional from certain pressures (for example, the pressure to cut corners to save money) by
making it reasonably likely (and more likely then otherwise) that most other members of the
profession will not take advantage of her good conduct. A code is a solution to a coordination
problem.
My hope is that this report will help inspire a code of ethics for web developers, guiding our work in
a way that is professional and inclusive.
The approaches I’ve laid out are merely my take on how web development can provide the greatest
happiness for the greatest number of people. These approaches are likely to evolve as technology
changes and may be unique for many development situations. I invite you to read my practical
application of these ideas and hope that you apply them in some fashion to your own work.
This series is a work in progress, and I invite you to contribute. To learn more, visit the Ethical Web
Development website.
Intended Audience
This title, and others in the Ethical Web Development series, is intended for web developers and
web development team decision makers who are interested in exploring the ethical boundaries of
web development. I assume a basic understanding of fundamental web development topics such as
HTML, JavaScript, and HTTP. Despite this assumption, I’ve done my best to describe these topics in
a way that is approachable and understandable.


Chapter 1. Introduction
In 1998, Tim Berners-Lee, the creator of the Web, published “"The World Wide Web: A Very Short
Personal History”. In this brief essay, he states:
The dream behind the Web is of a common information space in which we communicate by
sharing information. Its universality is essential: the fact that a hypertext link can point to

anything, be it personal, local or global, be it draft or highly polished.
To Berners-Lee, the universality of the Web is exactly what allowed it to grow from a single server
at his desk to a global communication network with over three billion users worldwide.1 While built
upon the technologies established in those early days, today’s Web has grown beyond the concept of
hyperlinked documents. Today, we build rich graphical interfaces that encompass anything from a text
document to a real-time video application, while also providing the primary means for personal
interaction, information, and fundamental social services for many users.
With the rise of information and immersive applications on the Web, we have created a global
network that society relies upon. Pausing to think about this, it is a beautiful thing and, true to
Berners-Lee’s vision, there remains little barrier to entry to publishing a site or application.
However, as web developers, it is a professional and social responsibility to ensure that our sites
and applications work for as many people as possible.
I have often been tempted to regard browser or device testing casually in favor of using the latest and
greatest tools and browser features. Learning to use these new tools is one of the things that make web
development so enjoyable, but we must temper this desire with the ability to build sites that work for
as many users as possible. We should avoid shutting out users or denying them our services due to
technical constraints. When we do this, we are taking an elite position, potentially shutting out the
poor, disabled, and elderly. Imagine a storefront that didn’t allow customers to enter if their shoes
and clothes were too old. As a society we would find that offensive, and the shopkeeper would likely
be publicly disgraced on the evening news. However, we often put banners on our site that say, “This
site only supports X browser or newer,” when a visitor accesses it with an older browser. Or worse,
the site will silently fail, akin to the shopkeeper completely ignoring a customer.
It Just Works
My wife and I began dating in 2003, and within a year or so I became her family’s default “computer
expert.” In 2005, I helped my father-in-law, Marty, pick out a new computer for himself. To him, this
was akin to an appliance purchase and we picked out a sturdy desktop computer, which has been in
continuous use since then. We’ve made some upgrades to the RAM and I’ve done my best to point
him to using an evergreen browser that automatically updates, but those no longer update on his aged
XP system. When I asked him why he doesn’t upgrade, he just shrugs and says “it still works.” For
him, the existence of the web browser is enough. He assumes that by typing in a URL, that the

browser and machine connecting shouldn’t make a difference.
When my grandfather passed away, my grandmother, Kathy, wanted to learn to use a computer and
connect to the Web. Her primary device is an inexpensive and outdated Android tablet that connects
to the Web through a wireless connection from the rural area where she lives. She uses it to check
Facebook, read the news, read books, and play solitaire.
As developers, we want to assume that people like Marty and Kathy are edge cases. Looking at the
top browsers currently in use, when grouped together, device-specific browsers, outdated
“evergreen” browser versions, and uncommon open source browsers occupy the second largest
percentage of market share (see Figure 1-1).2 Though each of these browsers and versions may only
show up in our analytics as a fraction of a percent, when grouped together they become a powerful
representation of the market.

Figure 1-1. Top browsers currently in use (nonstandard and outdated browsers comprise over 12% of the international
browser market)

Though the users of these browsers may not be the target demographic for our applications and
services, by not accommodating for them we are denying them the opportunity to participate.
A Responsibility
As web developers, we are gatekeepers to the vast troves of information and interaction across the
Web. With this comes a responsibility to ensure that the Web is an open and inclusive space for all.
The following chapters attempt to lay a groundwork for inclusive web development through:
Progressive enhancement


By building progressively we can ensure that all users have access to a base experience,
regardless of technology or network conditions.
Accessibility
By building accessible user interfaces, we ensure that everyone has equal access to our

applications regardless of disability or age.
Inclusive forms
Forms allow users to interact directly with the Web, making it a two way form of communication.
By creating web forms that are inclusive and usable, we demonstrate our dedication to inclusion.
1 Number

of Internet Users (2016) - Internet Live Stats, />
users/.
2 The

site StatCounter provides these metrics on its website. I’ve made the full list available as a
CSV at />

Chapter 2. Progressive Enhancement
Progressive enhancement is a term that often incites intense debate. For many, progressive
enhancement can be summed up as “make your site work without JavaScript.” While developing a
site that works without JavaScript often does fall under the umbrella of progressive enhancement, it
can define a much more nuanced experience.
In Aaron Gustafson’s seminal A List Apart article “Understanding Progressive Enhancement”, he
describes progressive enhancement as a peanut M&M: the peanut is the core experience, which is
essential to the user. The chocolate is the features and design that take us beyond the naked peanut
experience and add some much-loved flavor. Finally, the candy shell, though not necessarily needed,
provides added features, such as not melting in your hand. Often this example uses HTML as the
peanut, CSS as the chocolate, and JavaScript as the candy shell.
In today’s web application landscape it may be an oversimplification to consider progressive
enhancement as simply “works without JavaScript.” In fact, many of the rich interactions and
immersive experiences that have come to define the modern Web certainly require JavaScript. For
progressive enhancement to be considered an ethical issue in web development, we must tie it back to
user needs. Progressive enhancement is about defining what users need to get from your website and
ensuring that it is always delivered to them, in a way that will work regardless of network conditions,

device, or browser.
I prefer Jeremy Keith’s view of progressive enhancement as a “process” rather than a specific
technique or set of technologies. By Keith’s definition, this process looks like:
1. Identify the core functionality
2. Make that functionality available using the simplest technology
3. Enhance!
As developers, it is our job to define the core functionality of our applications and establish what
enhancements entail. This allows us to develop a baseline to build from—but the baseline for any
given project may be different.
In his 2012 article “Stumbling on the Escalator”, Christian Heilmann appropriated a Mitch Hedberg
comedy bit about escalators for progressive enhancement:
An escalator can never break—it can only become stairs. You would never see an “Escalator
Temporarily Out Of Order” sign, just “Escalator Temporarily Stairs. Sorry for the convenience.
We apologize for the fact that you can still get up there.”
As a person who has spent a lot of time in Washington DC’s Metro system, I can really appreciate
this analogy. Fortunately, when an escalator is out I am not trapped underground, but instead can huff


up the now-stairs to the street.
Often, when beginning a project, I am presented with a set of business requirements or a beautiful
design. From these, it can be easy to see the end goal, but skip the baseline experience. If, in the case
of the escalator, my requirement was to “build a transportation system that will allow Metro riders to
travel from the terminal to the street,” my initial reaction may be to create only an elevator. You can
imagine how this might become problematic.
Developing web apps works in much the same way. If we only consider the end goal, we run the risk
of leaving our users stranded. By focusing on and providing a solid baseline for our users, we set
ourselves up for success in many other aspects of ethical web development, such as accessibility and
performance.
Defining Core Functionality
If progressive enhancement is the process of defining a core functionality and building up from there,

how do we define that initial baseline? The goal is to consider the bare minimum that a user requires
to use our application. Once we have defined this, we can layer on additional style and functionality.
For some applications, this may be a completely JavaScript-free version of the experience, while for
others it may be a less fully featured version; for still others it may be providing some serverrendered content on the initial page load only.
The key is to think of progressive enhancement not as a binary option, but instead as a range,
determining what is the best decision for users. In this way, progressive enhancement is a gradient
rather than an either/or option (see Figure 2-1). Our responsibility is to decide where on this gradient
our particular application falls.

Figure 2-1. Progressive enhancement is a gradient of choices

I’d encourage you to take a few minutes and consider what the core functionality might look like for a
few different types of websites and applications, including the following:
News website
Social network (write text posts and read your newsfeed)
Image sharing website
Web chat application
Video chat application
Identify the primary goal of each type of site and determine the minimum amount of technology needed


to implement it. To take it a step further, write some markup or pseudocode explaining how you might
implement those baselines and features.
When working on your own applications, try to perform the same exercise. First, determine the core
functionality for your users and build the application from there. This programmatic approach also
pairs well with the Agile approach to software development, where the goal is to deliver working
software at the end of each development sprint. If we first deliver a core experience, we can
iteratively build upon that experience while continuing to deliver value.
Progressive Enhancement Is Still Relevant
Some may question how relevant progressive enhancement is today, when a small percentage of users

browse the Web with JavaScript disabled.1 This places the focus too heavily on progressive
enhancement as a JavaScript-free version of a site. In fact, some types of applications, such as video
chat, absolutely require some form of JavaScript to work in the browser. The goal of progressive
enhancement is to provide the absolute minimum for a working product and ensure that it is delivered
to each user’s browser.
Ideally, this working minimum product is simply HTML without any external resources such as
images, video, CSS, or JavaScript. When users’ browsers request our site, we can be certain that they
will receive HTML (or nothing at all). By creating a working version of our application, even with a
minimal experience, using the smallest number of assets, we can be sure that the user is able to access
our content in some form.
The Government Digital Service team (GDS) at GOV.UK provides a number of scenarios where
asset requests may fail:
Temporary network errors
DNS lookup failures
The server that the resource is found on could be overloaded or down, and fail to respond in time
or at all
Large institutions (e.g., banks and financial institutions, some government departments) having
corporate firewalls that block, remove, or alter content from the Internet
Mobile network providers resampling images and altering content to make load times faster and
reduce bandwidth consumed
Antivirus and personal firewall software that will alter and/or block content
Additionally, in the blog post “How Many People Are Missing Out on JavaScript Enhancement?”, the
GDS added the following:
Existing JavaScript errors in the browser (i.e., from browser add-ons, toolbars, etc.)


Page being left between requesting the base image and the script/noscript image
Browsers that preload pages they incorrectly predict you will visit
While those of us developing for the Web often have nice hardware and speedy web connections, that
may not be true for many of our potential users. Those in developing or rural areas may have limited

or outdated devices and slow connections. In 2015, the Facebook development team initiated a
program called 2G Tuesdays, which allows them to experience their applications as though they are
being served over these slower networks. I would encourage you to do the same.
Today’s browser development tools allow us to mimic network conditions, experiencing what it is
like for these users to access our sites (see Figure 2-2). We will explore the topic of web
performance in greater detail in an upcoming title in this series.

Figure 2-2. The Google Chrome browser includes network connectivity simulation tools

Though you may have never used, tested an application with, or even heard of it, the Opera Mini
browser currently has over 300 million users worldwide.2 The browser is designed to greatly
decrease mobile bandwidth usage by routing pages through Opera’s servers and optimizing them. To
do this, Opera Mini only supports a subset of modern web standards. Here are a few of the things that
are unsupported by Opera Mini:
Web fonts (which also means no icon fonts)
HTML5 structural elements and form features
Text-decoration styling
Video and audio elements
The site Opera Mini Tips collects the full set of modern web standards that are not supported in the
browser. As you can imagine, without a progressive enhancement strategy, our sites may be
completely inaccessible for all 300+ million Opera Mini users.


When developing an application exclusively for users who are likely in an urban area with strong
Internet speeds and nice hardware, we may feel as if we are exempt from concerning ourselves with
connection issues. Recently, developer Jake Archibald coined the termed Lie-Fi. This is a connection
where our mobile device seems to be connected to WiFi, but sites are slow to load as they feebly
connect to our struggling signal.
In addition to the conditions just described, there may be external factors at play. In 2014, the UK’s
Sky broadband accidentally blocked the jQuery CDN for a brief amount of time, presumably leaving

many users perplexed with broken websites. More recently, the ability to compose and publish a
tweet became unavailable in the Twitter web client. This was caused by a regular expression that
was being served by a CDN without the proper character encoding. Though the JavaScript likely
worked in all local and quality assurance testing, once it was available on the Web it disabled one of
the site’s most critical features.
Run Your Own Experiment
GDS was curious to see how many users were missing out on JavaScript resources when accessing
its site. To test this, the team ran an experiment by adding three images to a page:
An image that all browsers should request
An image that would only be requested via JavaScript
An image that only browsers with JavaScript disabled would request
The results of this experiment are really fascinating. Though only a fraction of a percentage of users
requested the JavaScript-disabled image, those that failed to load the image requested via JavaScript
were significantly higher.
If possible, I’d encourage you and your teams to conduct a similar experiment. This allows us to base
the decision to support (or not support) Javascript-disabled users with data, rather than assumptions
or world averages.
To run this experiment on your own site, first create three empty GIF files named base-js.gif, withjs.gif, and without-js.gif. Then you can use the following snippet (adapted from GOV.UK’s
experiment) in your HTML:
style="position: absolute; left: -9999em; height: 0px;
width: 0px;">
<script type="text/javascript">
(function(){
var a = document.createElement("img");
a.src = "with-js.gif";
a.alt = "";
a.role = "presentation";
a.style.position = "absolute";
a.style.left = "-9999em";

a.style.height = "0px";
a.style.width = "0px";
document.getElementById("wrapper").appendChild(a);
})();
</script>
<noscript>
style="position: absolute; left: -9999em; height: 0px;
width: 0px;">
</noscript>

WEB BEACONS
This approach, used by GOV.UK, is a recommendation to use web beacons, which may have some privacy implications.
Web beacons are typically hidden pieces of content used to check if a user has accessed a piece of content, and are
common in email marketing campaigns. Privacy issues such as this will be discussed in an upcoming title in the series.

How Can We Approach Progressive Enhancement Today?
Recently, I was talking with my friend and colleague Scott Cranfill about a progressive enhancement
strategy for a project he was working on. This project was mostly static content, but also included an
auto loan calculator. When discussing how he might approach this from a progressive enhancement
angle, he mentioned that he thought the default markup should simply include the formula that the
calculator uses. Once the page’s assets load, a fully functional dynamic calculator will display. This
means that nearly every user will only see and interact with the calculator, but should something go
wrong, a user will still be presented with something that is potentially useful. I loved this pragmatic
approach. It wasn’t about “making it work without JavaScript,” but instead about making it work for
everyone.
In the world of modern, JavaScript-driven web applications, there are still several practical
approaches we can take to build progressively enhanced sites. These approaches can be simple or

leverage exciting web technology buzzwords such as isomorphic JavaScript or progressive web
applications. Because progressive enhancement is not a one-size-fits-all approach, you may want to
evaluate these and choose the one that best works for your project.
Let’s take a look at a few of these options and how they may be used to build the best possible
experience for a user.
Perhaps the simplest and most progressive is to completely avoid a JavaScript-dependent first-page
render. By rendering all of the necessary content on the server, we can ensure that users receive a
usable page, even if only our HTML makes it to their browser. The key here is to focus on what is
necessary. There may be additional JavaScript-required functionality, but if it isn’t necessary we can
allow it to quietly fail in the background or present the user with different content.
If you choose to serve a library from a CDN, you should provide a local fallback as well, as
recommended by HTML5 Boilerplate’s. This allows us to leverage the benefits of the CDN while


ensuring that the user has the opportunity to downloads the scripts should there be an issue with the
CDN, such as unexpected down time or being blocked by an ISP or third-party browser add-on.
Here’s the code you’ll need to use:
<script src=" /></script>
<script>
window.jQuery || document.write(
'<script src="js/vendor/jquery.min.js"><\/script>'
)
</script>

Another option, or one that may paired with the previous, is to sniff out outdated browsers and avoid
serving JavaScript to those browsers. We can continue to serve our core content and functionality to
those browsers (it was progressively enhanced, after all!), but offer a significantly simpler
experience.
To sniff out older browsers, we can use a technique demonstrated by Jake Archibald from his 2015
Nordic.js talk. This checks for the availability of the Page Visibility JavaScript API, which is only

available in modern browsers. If Page Visibility is unavailable, the code exits without attempting to
execute. You can use the following code to check for the Page Visibility API:
(function() {
if (!('visibilityState' in document)) {
return false;
}
// rest of your code
}());

IIFE
The preceding example is wrapped in an immediately invoked function expression (IIFE), which may look a bit odd if you’re
not a JavaScript developer. This ensures that the code executes immediately while avoiding the pollution of the global
scope. If you are interested in learning more, see Ben Alman’s detailed post about IIFEs.

For JavaScript-dependent applications, we could render the landing page as HTML on the server
while prefetching the JavaScript for the rest of the application:
<link rel="prefetch" href="app.js">

This approach gives our users the opportunity to download and cache the application’s JavaScript,
without impacting the performance or requirement on a mostly static page. Soon browsers will begin
implementing the Preload specification, which will be similar to prefetch, but enable additional
browser features.


In action, preload looks similar to prefetch:
<link rel="preload" href="app.js" as="script">

Here are some prefetch and preload resources:
Robin Rendle’s “Prefetching, Preloading, Prebrowsing”
Luis Vieira’s “HTML5 Prefetch”

Yoav Weiss’s “Preload: What Is It Good For?”
You may be thinking, “But I want to build modern JavaScript web applications.” Certainly these
techniques feel out of sync with the approaches of some of the popular JavaScript frameworks, but
recently we’ve seen the most popular web application approaches trend back toward a progressive
enhancement model.
Isomorphic or universal JavaScript is a technique that allows a developer to pair server-side and
client-side JavaScript into a “write once, run everywhere” approach. This technique means that the
initial application will render on the server, using Node.js, and then run in the browser. When
building a progressively enhanced isomorphic application we can start by building our serverrendered version of the applications and layer on the isomorphic approach.
A similar approach was taken by the team behind the recent Google+ redesign:
With server-side rendering we make sure that the user can begin reading as soon as the HTML
is loaded, and no JavaScript needs to run in order to update the contents of the page. Once the
page is loaded and the user clicks on a link, we do not want to perform a full round-trip to
render everything again. This is where client-side rendering becomes important—we just need
to fetch the data and the templates, and render the new page on the client. This involves lots of
tradeoffs; so we used a framework that makes server-side and client-side rendering easy
without the downside of having to implement everything twice—on the server and on the client.

ISOMORPHIC JAVASCRIPT
Though my description may be oversimplified, isomorphic JavaScript is an exciting approach for developers and teams who
are using server-side JavaScript. To learn more about isomorphic JavaScript, I recommend taking a look at the following
resources:
Building Isomorphic JavaScript Apps by Jason Strimpel (O’Reilly, 2015)
Spike Brehm’s “Isomorphic JavaScript: The Future of Web Apps”
Jack Franklin’s “Universal React”

If a fully isomorphic JavaScript approach is overkill for an application, Henrik Joreteg has coined the
term lazymorphic applications. A lazymorphic application is simply one where the developer pre-

renders as much of the application as possible as static files at build time. Using this approach, we
can choose what we render, making something useful for the user while withholding JavaScriptdependent features.
Lastly, the term progressive web apps has recently taken hold. Rather than specific technology, this
term has come to encompass several interrelated techniques and approaches to web development.
This is an approach that pairs nicely with all of those listed earlier.
In his article “Progressive Web Apps: Escaping Tabs Without Losing Our Soul”, Alex Russell
described progressive web applications in this way:
Responsive
Connectivity independent
App-like interactions
Fresh
Safe
Discoverable
Re-engageable
Installable
Linkable
The progressive web application approach just described is well aligned to an ethical web
application experience by focusing on delivering an application experience that works for every user.

PROGRESSIVE WEB APPLICATIONS
Though rooted in several technologies, the overarching concept of progressive web applications is just starting to take hold.
Here are a few of the resources that I’ve found most useful for getting started:
Google Developers: Progressive Web Apps
Progressive Web Apps HQ
Getting Started with Progressive Web Apps

In Summary
There are a variety of techniques and approaches that allow us to build progressively enhanced
modern websites and applications. This chapter has outlined a few of these options. By beginning
with the core functionality, we are able to ensure that our application works for the maximum number

of people. This provides us with a baseline to provide working software for all users in a range of


situations.
From an ethical standpoint, progressive enhancement provides several benefits to our users. By
following a progressive enhancement process, we can be sure that we are building our applications in
a way that allows them to be available for as many users as possible, regardless of device,
connection, or browser.
Additional Resources
Aaron Gustafson’s “Understanding Progressive Enhancement”
GOV.UK’s “Progressive Enhancement: How to Create Pages That Work Regardless of Browser
Capability”
The Responsive News blog’s “Cutting the Mustard”
Jake Archibald’s “Progressive Enhancement Is Still Important”
Ponyfoo.com’s “Stop Breaking the Web”
1 In 2010,

Yahoo conducted what is considered the definitive study of JavaScript usage, finding that
the percentage of users with JavaScript disabled ranged from 0.26% to 2.06%, depending on the
country of origin. Sadly, these statistics are long out of date. In 2013, GOV.UK’s GDS team did a
similar study and found that 1.1% of its users were not receiving JavaScript. The German site
darwe.de analyzes JavaScript enablement in real time and shows a much larger percentage of users
with JavaScript disabled visiting its site.
2 Owen Williams,

“The Unknown Browser with 300 Million Users That’s Breaking Your Site,”
TNW, />

Chapter 3. Web Accessibility
The power of the Web is in its universality. Access by everyone regardless of disability is an

essential aspect.
—Tim Berners-Lee, Inventor of the World Wide Web
Building accessible websites and applications means making those sites available to users regardless
of physical ability. This covers a broad range of disabilities, such as visual, physical, auditory,
cognitive, and age-related disabilities. When we build with accessibility in mind, we make an ethical
decision of inclusion. Alternatively, when we choose to ignore accessibility, it excludes people with
disabilities from participating in the Web.
Today, as web users, we access government services, educational resources, bank transactions,
social interactions, work tasks, healthcare, entertainment, and more through our web browsers. As the
Web continues to play an increasingly large role in our daily lives, this causes inaccessible websites
to be a hurdle to fully participating in society. With the importance the Web plays in our society, it
has become our responsibility as developers to ensure its equal access to all.
The W3C summarizes the social issues around web accessibility in three principles:
It is essential that the Web is accessible in order to provide equal access and equal opportunity to
people with disabilities.
The Web is an opportunity for unprecedented access to information for people with disabilities.
The Web is an opportunity for unprecedented interaction for people with disabilities.
The W3C has also called out that the United Nations Convention on the Rights of Persons with
Disabilities expresses that accessibility across the web has become a human right. Specifically it
states:
To enable persons with disabilities to live independently and participate fully in all aspects of
life, States Parties shall take appropriate measures to ensure to persons with disabilities
access, on an equal basis with others […] to information and communications, including
information and communications technologies and systems[…].
States Parties shall take all appropriate measures to ensure that persons with disabilities can
exercise the right to freedom of expression and opinion, including the freedom to seek, receive
and impart information and ideas on an equal basis with others and through all forms of
communication of their choice[…].
When done correctly, an accessible Web not only provides equal access to services and information,
but also empowers those with disabilities.

Chapter 3. Further Reading
W3C’s “Social Factors in Developing a Web Accessibility Business Case for Your Organization”
W3C’s “Designing for Inclusion”
Broadening the Scope of Accessibility
The need for accessibility is not limited to those with permanent disabilities. Accessible web
interfaces may benefit a range of users.
As of the 2010 census, there are 17 million people 75 years of age and older living in the United
States. Worldwide, over 8% of the earth’s total population falls into the 65 and above category. This
age group has consistently grown as a percentage of the total population, creating an increasing
market segment. With an aging population, there are several factors that can impact the use of the
Web, most notably motor and vision impairments. By building with accessibility in mind, we are able
to accommodate users of all ages.
In addition to those with permanent or age-related disabilities, many users may have temporary
disabilities. Often these may be related to an injury where vision or motor abilities are impaired.
Further Reading
Melody Kramer’s “News for Betty”
W3C’s “Meeting the Needs of Aging Web Users”
The A11Y Project’s “MYTH: Accessibility Is ‘Blind People’”
Web Content Accessibility Guidelines
In 2008, the W3C released an update to the Web Content Accessibility Guidelines, commonly
referred to as WCAG 2.0. This document covers a range of success criteria for creating accessible
web content. Rather than focusing on specific technologies, the document offers suggestions for
making all websites and applications more accessible.
POUR
The guidelines and success criteria of building WCAG 2.0 accessible web applications are organized
around the POUR principle. POUR stands for Perceivable, Operable, Understandable, and Robust.
Following these guidelines allows us to build websites and applications that are usable by all. Let’s
take a closer look at each of these guidelines:

Perceivable
Information and user interface components must be presentable to users in ways they can
perceive.